/**
 * Created by 二更 on 2017/4/17.
 */
$(function(){
    function scrollTxt(){
        var controls={},
            values={},
            t1=300, /*播放动画的时间*/
            t2=2000, /*播放时间间隔*/
            si;
        controls.rollWrap=$("#roll-wrap");
        controls.rollWrapUl=controls.rollWrap.children();
        controls.rollWrapLIs=controls.rollWrapUl.children();
        values.liNums=controls.rollWrapLIs.length;
        values.liHeight=controls.rollWrapLIs.eq(0).height();
        values.ulHeight=controls.rollWrap.height();
        this.init=function(){
            autoPlay();
            pausePlay();
        }
        /*滚动*/
        function play(){
            controls.rollWrapUl.animate({"margin-top" : "-"+values.liHeight}, t1, function(){
                $(this).css("margin-top" , "0").children().eq(0).appendTo($(this));
            });
        }
        /*自动滚动*/
        function autoPlay(){
            /*如果所有li标签的高度和大于.roll-wrap的高度则滚动*/
            if(values.liHeight*values.liNums > values.ulHeight){
                si=setInterval(function(){
                    play();
                },t2);
            }
        }
        /*鼠标经过ul时暂停滚动*/
        function pausePlay(){
            controls.rollWrapUl.on({
                "mouseenter":function(){
                    clearInterval(si);
                },
                "mouseleave":function(){
                    autoPlay();
                }
            });
        }
    }
    new scrollTxt().init();
});
